Lapping machine



June 27, 1933. A EI ROBINSON LAPPING MACHINE Filed April 13, 1951 3 Sheets-Sheet l l 3 /00 Egg/ 7- Tf Sheets LAPPNG MACHINE N G 5 m E O R E.

Filed April EVE/P3751. .E

MUT

June 27, 1933. A, E ROBINSON 1,916,117

LAPPING MACHINE Filed April 13. 1931 3 Sheets-Sheet 3 Patented June 27, 1933 UNITED STATES ALBERT E. ROBINSON, 0F CINCINNATI, OEIO,

Assieiion. To THE AMERICAN roei. wo'iifxs COMPANY, OF CINCINNATI, OEEO, A CGRPORATION OF OHIO LAPEING MACHINE Application led April 13,

My invention relates to lapping machines and has for its object the provision of new and improved means whereby gears may be lapped in meshing relation.

lt is the object ci my invention further to provide new and improved means for rotatlng the gears; lfurther, to provide new and improved means whereby shock between -..ie gears being lapped is avoided; further, to provide new and improved means for mounting the gears with relation to each other gv and, further, to provide new and iinproved means for causing movement oi the gears with relation to each other lengthwise of the teeth thereof.

The invention will be further readily'understood from the following description and claims, and from the drawings, in which latter:

Fig 1 is a plan view of my improved device.

Fig. 2 is an end elevation of the same.

Fig. 3- is a cross-sectional detail view of the same, taken on the line 3 3 of Fig. l.

Fig. A is a side elevation of my improved device, partly broken away.

Fig. 5 is a vertical section of a detail of the same, taken on the line 5 5 oi Fig. 1.

Fig. 6 is a cross-section of my improved device, taken on the line 6 6 of Fig. l.

Fig. 7 is a horizontal section showing a modication of the same, taken in the plane of the line 6 6 of F ig. el; and,

Fig. 8 is a vertical section showing a plural-ity of bushing structures and gears, taken in the plane ofthe line 8 8 of Fig. 6.

The present invention is an elaboration of the invention shown, described and claimed in my copending application for patent on improvement in lapping machines, filed in the United States Patent Oflice April 13, 1931. as SerialNo. 529,736.

A vframe 11 has a motor 12 mounted therein. This motor is exempliiied as an electric motor and is a reversible motor, sothat its rotor shaft 13 may be rotated in opposite direction for driving the mechanism operated thereby in opposite directions.

A housing 15 is mounted on the frame, being shown iiXed theretoL by bolts 16. A

i931. semi No. 529,735.-

drive shaft 17 is jouriialed in bearings 18l in the housing, and has a pulley 19' Xed thereto. A pulley 2O is fixed on the rotor shaft 13. A belt 21 is received about the pulleys for driving the drive shaft. The drive shaft is shown extending lengthwise of the frame. It may he rotated in reverse directions.

An arbor 24 is rotatable in bearings 25, 26, Y

into the tapered socket at the end of the bore for fixing the spindle to the sleeve and permitting removal of the spindle endwisel from the sleeve.

The frame is provided with guidewa-ys 41 extending lengthwise thereof, on which a slide l2 is adjustable toward and from `the housing 15. This adjustment is shown as a micrometer adjustment by means of a screw rod 43 journaled and held endwise in a bearing le at the end of the frame, and havingthreaded connection with a nut 45 fixed to the slide as by a bolt 4.6.

An arbor 5l is rotatable in bearings 52, 53, in a housing 54 on the slide 42, extending crosswise ,of the frame. This arbor comprises sleeve 55 having a. bore 56 enlarged asy a tapered socket 57 at one end, in which the tapered end 58 of a spindle 59 is received. A screw rod 60 has threaded connection 61 with the tapered end of said spindle, a washer 62 being interposed between the head 63 of the threaded rod bearing and the sleeve for drawing the spindle firmly into the sleeve and centering the spindle.

Master gears 65, 66, are arranged to be received in meshing relation about one of the ends or the arbors, and gears to be lapped 67, 68. are arranged to be received in meshing relation over the other of the ends of the spindles. The gears rotate with the arbors.

Spindles having' gear receiving portions of different diameters may be provided for gears to be lappedhaving diierent sized holes, so that the gears to be lapped are centered about the spindles and about the axes of rotation o3'` the arbors.

Filling collars 69 of different lengths are received over the spindles, washers 70 being at the outer ends of said collars and nuts 71 being threaded to the outer ends of said spindles for clamping the gears to be lapped and the collars between the ends of the sleeves and said nuts and washers. v

Any number of gears it is desired to lap may be placed side by side on the spindles so as to simultaneously lap a numberof pairs of such gears. (See Fig. 8.)

r[he drive shaft 17 has a bevel gear 75 lined thereto. (Fig. 6.) This bevel gear meshes with a bevel gear 76 mounted about the sleeve, the sleeve rotating with said bevel gear as by key connection 77. The bearings 25, 26, are shown as ball bearings, the outer raceways of which are received in annular abbets 78, 79, in the housing 15, being clampedin place by caps 80, 81, fixed to the outer ends of said housing, as by bolts 82, 83.

The inner raceways of the ball bearings 25, 26, are received about the outer circumference of the sleeve 27. The outer end of the inner raceway of the ball bearing 26 is received against a shoulder 84 of said sleeve. The inner raceways of said ball bearings are held in spaced relation by the bevel gear 76 and a collar 85. A collar 86 is received about said sleeve at the other end of the inner raceway of the ball bearing 25, a nut 87 being threaded over the sleeve for clamping the collars .and the inner raceways toward the shoulder S4.

A yieldable drive connection is provided between the arbor 24 and the gear 65, exemplified as comprising a block 91 rotating with the arbor, as by a key connection 92. (Figs. 1, 3 and 6.) Plungers 93 are received in sockets 94 in said block and have stems 95 received through holes 96 in the bottoms of said sockets. The outer ends of these stems are threaded and have nuts 97 threaded thereover. The plungers have heads movable endwise in said sockets. Springs 98 are located between said heads and the bottoms of said sockets, `for normally urging said plungers axially outward with relation to said sockets.

A hub 99 is rotatable on the arbor and has a flange 100 provided with lugs which coact with the plungers. These lugs are shown as pins 101 fixed in the flange at the respective sides o'f the arbor. These pins coact with the plungers. Adjustments of the nuts 97 adjust the plungers axially, with-relation to the'pins and adjust4 the tensions of the springs 98.

The block 91` is mounted on a. step 105 of the arbor between shoulders 106, 107, on said arbor. (F ig. 6.) yThe hub 99 is journaled on a. reduced end 108 of the arbor and coacts with the shoulder 106. A washer 34 holds the hub on the arbor. The gear 65 is received about the shank of said hub, the hub and gear rotating together, as by means of a key connection 109. A washer 110 is received about said shank, a nut- 111 being threaded to the threaded end of said shank for clamping the gear between a shoulder 112 on said hub and the washer.

Hubs having shanks of different diameters may be provided tor centrally locating gears thereon having holes of diiierent diameters.

A bushing 115 is received about one of the ends ofV the arbor 51 being located endwise against a shoulder 116 on the sleeve 55 of said arbor. (Fig. 6.) The bushing is provided with a flange 117. A washer 118 is received about said sleeve at the other end of said bushing, a nut 119 being' threaded over the threaded end 120 of said sleeve. The gear 66 is clamped between said ilange and said washer by said nut. The bushing rotates with the sleeve, as by means of a key connection 121. The gear rotates with the bushing as by means of a key connection 122. Bushings of diii'erent diameters may be employed for centering gears having holes of dilierent diameters.

Similar bushing structures may be received about the hub 99 and about the spindles 31, 59, for accommodating gears having holes ot Vdiierent diameters.

Fig. 8 shows a plurality of bushing structures and gears on one of the spindles.

The arbor 51 is rotatable in the bearings 52', 53, the-outer raceways ot said bearings being located in annular rabbets 127, 128, in the housing 54, caps 129, 130, being clamped against said outer raceways as by bolts 131, 132. V

A gear 135 is located about the sleeve 55, having drive connection with said sleeve as by means of a key connection 136. The inner raceways of said ball bearings are spaced apart, as by means of said gear and collar 137. A collar 138 is at the outside of the inner raceway of the ball bearing 125, a nut 139 being threaded over the threaded por ion 140 of said sleeve for clamping said last-named collar and inner raceway between said nut and an annular shoulder 141 on said sleeve, and clamping the collar 137, the gear 135 and the inner raceway of the ball bearing 126 toward a shoulder 142 of the sleeve 55. i

Lubricant shields 143, 144, are received about the arbors 24, 51, between shoulders 145, 146, thereon, and the respective gears to be meshed 67, 68.

In the form of the invention shown in Figs.

the sets of gears, so as to cause lapping action between the teeth of said gears across the width of said teeth. For this purpose the housing 54 is mounted on a cross slide 151 on the slide 42'. The slide 42 is provided with guides 152 with which a guideway 153 on the cross-slide coacts.

The housing 54 is provided with bearings 154, 155, 156, in which shafts 157, 158, 159, rotate. The shaft 157 has a bevel gear 160 thereon which meshes with the bevel gear 135. The shaft 157 is also provided withka pinion 161. The shaft 158 is provided with a gear 162 meshing with the pinion 161, and with a pinion 163 which meshes with a gear 164 on the shaft 159. The shaft 159 is provided with a crank 165.

A. bearing 168 on a link 169 is received about said crank at one end of said link. The other end of said link has a bearing 17 O about a pin 171 in a stand 172 fixed to the slide 42, forming articulating connection between said link and said cross slide. This construction converts the rotary movement of the crank into reciprocating linear movements of the cross slide, and imparts endwise movements to the arbor 51 and the gears mounted thereon.

In the modification shown in Fig. 7, this endwise reciprocation of the arbor is omitted, and the spacingcollar 175 is elongated for the distance between the inner raceways of the ball bearings about the arbor 51 for locating said inner raceways.

The spindle is also shown in Fig. 8 as having bushing structures received thereover for centering gears having holes larger than the diameter of the shank of the spin dle 59. The bushing parts are designated by similar but primed reference numerals. Such bushing structures of dilferent diameters and lengths may be received about either of the spindles, about the hub 99 and about the other end of the arbor51, for accommodating and centering gears having different sized holes.

In operation, rotation in a given direction is imparted to the drive shaft by operation of the rotor of the motor in one direction. This causes rotation of the drive shaft in a given direction for causing rotation of the arbor 24 in a given direction. The master gears 65, 66, are provided with teeth of proper form, pitch and depth for determining the form, pitch and depth of the teeth of the gears to be lapped after the lapping of the same.

The gears to be lapped usually have their teeth cut or formed thereon and are then hardened. The hardening of the gears causes change of form in the gears or some or all of the teeth, and the object of the lapping is to reduce or reshape th-e teethto their proper forms. The hardened gears may for instance have high spots on their teeth, or the teeth or parts thereof may be warped, or their surfaces may be rough or uneven,

these objectionable conditions being re1n edied by the lapping.

The lapping is performed by meshing the gears to be lapped together, and supplying a lapping compound, as a mixture of powdered carborundum and grease, either manually or automatically to the teeth, as by means of a. brush, or a pipe feeding the compound to the gears to be lapped.

When uneven or untrue parts of the teeth to be lapped engage each other in the lapping operation, a momentary excess resistance may take place between the gears. This is compensated for by the yielding drive connection in the train of gearing. If for in- Stance such an unusual resistance between the gears being lapped is encountered, one or the other of the plungers 93 in the plunger block 91, depending on the direction in which the arbor is being rotated, will yield to such excess resistance, causing compression of the spring, which offers additional resistance to the yield and counteracts the excess resistance between the gears being lapped, permitting the continuance of rotation of the gears without shock to the parts, and avoiding a misshaping of the teeth at such points of excess resistance, which would be likely to take place if the drive connection for the gears were rigid.

The nuts 97 are normally spaced from the block so as to supply cushioning means in both directions of rotation of the yieldable drive connection. If excessive resistance is had between the gears being lapped there will be a yield of one of the driving plungers and a following movement of the other driving plunger toward its companion pin which is receding from it. This is exemplified in Fig. 3, in which the plungers 93 are exemplified as rotating in the direction of the arrow a, for causing driving force to be applied Ybetween the left hand plunger and the left hand pin shown in this figure. A yield of the plunger due to resistance between the gears being lapped is shown.

The adjustment of the slide 42 is such that proper meshing relation between the gears being lapped is obtained for making contact between the high points or most misshapened portions of the teeth thereof. As these high points are worn away during operation, the slide 42 is adjusted toward the arbor 24 for causing approach between the master gears and between the gears being lapped. This adjustment is a micrometer adjustment for accurate approach between vthe gears in minute steps so as to relieve strain from the gears. This adjustment of the slide takes place until the master gears are in properly meshed relation, whereupon the teeth of the gears `being meshed are also of proper form and in properly meshed relation.

Rotation of the arbors in one direction causes lapping of one-of the sides of the teeth CII of the gears being lapped. Rotation of the drive shaft and arbors lin the opposite direction, caused by reversal of rotation of the rotor of the electric motor, causes lapping of the opposite sides of the teeth of the gears being lapped. These changes in directions of rotation may take place in steps during the lapping, or the lapping of one of the sides of the teeth may be completed before the lapping of the other sides of the teeth is begun.

y During such lapping axial movement is imparted to the arbor 5l for imparting endwise movement between the teeth of the gears being lapped, in order to lap the sides of the teeth of the gears being lapped uniformly throughout their widths and to prevent, for instance, the forming of grooves by the continued coaction in one position of hard spots on coacting faces of the teeth.

In the modification shown in Fig. 7 this axial movement of the arbor 5l and relative axial movement between the gears being lapped is omitted.

My improved device provides simpl-e, con pact and durable means for lapping gears of various diameters and widths. holes of various diameters, anl ready, simple and easily operated means for placing the gears in the machine anc ecnrng them in their relative positions, d adjusting the same, and simple and e iective means for preventing shock between lie gears and thereby improving the lapped surfaces between the teeth of the gears, and for providing endwiserreciprocation between the gears being lapped.

Having thus fully described my invention, what I claim as new, and desire to secure by Letters Patent, is:

l. In a gear lapp'n bination of a pair of ar rs, means for mounting a pair of master gears about the axes of rotation of said arbors, means for mounting a pair of work gears about the axes of rotation of said arbors, means for adjusting the distance between said arbors, driving means for rotating said arbors and gears including a resilient rotarily yielding rotary drive connection between one of said arbors and having g i iachine, the com- 4and one of said gears taereon.

2. In a gear lapping machine, the combination of a pair of arbors, means for mounting a pair of master gears about the axes of rotation of said arbors, means for mounting a pair of work gears about the axes of rotation of said arbors, means for adjusting the distance between said arbors, means for rotating said arbors and gears including a resilient rotarily yielding rotary drive connection between one of said arbors and one of said gears thereon, and means for axially reciprocating one of said arbors.

3. In a gear lapping machine, the combination of a frame, a housing thereon, a drive shaft on said housing extending lengthwise of said frame, an arbor on said housing extending crosswise of said frame, a mounting rotatively loose on said arbor, means on said mounting for releasably securing a gear to said mounting, means on said arbor for releasably securing a gear thereto, a yieldable drive connection yieldable in both directions of rotation between said arbor and said mounting, a slide, an arbor on said slide extending crosswise of said frame, means on said last-named arbor for releasably securing gears thereto in meshing relation with said first-named gears, means for adjusting said slide toward and from said housing for adjusting the meshing relations between said gears, and means vfor rotating said drive shaft in reverse directions.

4. In a gear lapping machine, the combi ation of a frame, a housing thereon, a drive shaft on said housing extending lengthwise of said frame, an arbor on said housing extending crosswise of said frame, a mounting rotatively loose on said arbor, means on said mounting for lrelcasrdoly securing a gear to said mounting, means on said arbor for releasably securing a gear thereto, a yieldable drive connection yieldable in both directions of rotation between said arbor and said mounting, a slide, an arbor on said slide, extending crosswise of said frame, automatic means on said slide for automatically reciprocating4 said last-named arbor endwise, means on said last-named arbor for releasably securing gears thereto in meshing relation'with saidfirst-named gears, means for adjusting said slide to 7ard and from said honsingfor adjusting the meshing relations between said gears, and means for rotating said -drive shaft in reverse directions.

5. In a gear-lapping machine, the combination of a frame, bearings thereon extending crosswise of said frame, arbors in said respective bearings, gear mountings on the respective ends of said arbors, said mountings onvoneof the ends of said arbors arranged for receiving meshing master gears, said mount-ings on theother of the ends of said arbors arranged for receiving meshing work-gears, said mountings including a yielding mounting, a yielding drive connection vyieldable in both directions of rotation between said yieldable mounting and its arbor, micrometer means for adjusting the distance between said arbors for adjusting the meshing relations between said master gears and between said worlr gears, and automatic reciprocating means for automatically axiallyreciprocating one of said arbors.

6. In a gear lapping machine, thc combination of a drive shaft and a pair of arbors arranged for yieldingly driving said gears.

7 In a gear lapping machine, the combination of a pair of arbors for receiving intermeshing gears to be lapped, a slide for one of said arbors extending lengthwise of .said arbor, means for rotating said arbor, a .driving gear about said arbor, a series of cross shafts on said slide, meshing reducing gearing on said cross shafts forming a train of reducing gearing comprising a high` speed gear in mesh with said driving gear and a low speed gear, a crank rotating with said low speed gear, a link, and a bearing atone end of said link about said crank, and the other end of said link having articulating connection with said slide whereby to reciprocate said slide and said arbor in the direction of the axis of rotation of said arbor and to cause shiftable positioning between the teeth of said intermeshing gears lengthwise of said teeth.

8. In a gear lapping machine, the combination of afpair of arbors, means for rotating ,one of said arbors, one of the ends of said arbors of each ot said arbors arranged for receiving master gears, the other of the ends of each of said arbors arranged for receiving gears to be lapped, means .tor adjusting the.

distance between said arbors for adjusting meshing relations between said gears, and means at each orn said ends of said arbors for centering gears having holes of different diameters on said respective ends.

9. In a gear lapping machine, the combination ot a pair ot arbors, means for mounting a pair of master gears about the axes of rotation of said arbors, means for mounting a pair of work gears about the axes of rotation of said arbors, said arbors and gears forming a driving train including a resilient rotarily yielding rotary drive connection between said master gear and said work gear about the axis of rotation of one of said arbors.

10. In a gear lapping machine, the combi-V nation of a support, a second support, an arbor on each of said supports, a mounting rotatively loose about one of said arbors, means on said mounting for releasably securing a gear thereto, means on said one of said arbors for releasably securing a gear thereto, a resiliently yieldable drive connection resiliently yieldable in both directions of rotation between said arbor and said mounting, means on the other of said arbors for releasably securing gears thereto in meshing relation with said rst-named gears, said gears including meshing master gears and meshing worl: gears, and means for adjusting the distance between said supports for adjusting the meshing relation between said gears.

ll. In a gear lapping machine, the combination ot a pair of arbors arranged for receiving master gears and work gears forming a train of driving means, said train of driving means including a yieldable rdrive connection comprising a pair of drive parts, and a pair of spring pressed plungers and lugs coacting with sai-d plungers, .said spring pressed plungers and said lugs respectively located at the respective sides of an axis of rotation in said train of driving means, one of said drive parts rotatively loose about the axis of rotation of one of said arbors and the other of said drive parts rotativ-ely secured to said last-named arbor, and said spring pressed plungers and said lugs mounted on said respective drive parts.

l2. In a gear lapping machine, the combination of a pair of supports, an arbor on leach of said supports, a gear mounting on one of said supports, means on said mounting for releasably securing a gear thereto, said arbor on said one of said supports provid-ed with means 'for releasably securing a gear thereto, a resiliently yieldable drive connection yieldable in both directions of rotation between said last-named arbor and said mounting, the other of said arbors provided with means or releasably securing gears thereto in meshing relation with said first-named gears, said gears including meshing master gears and meshing work gears, means for adjusting the distance between said supports for adjusting the meshing relations between said gears, and means for rotating said gears in reverse directions.

In testimony whereof, I have hereunto signed my name.

ALBERT E. ROBINSON. 

